ISO INTERNATIONAL STANDARD 21690 Second edition 2021-11 Glass in building Glass blocks - Specification and test methods Verre dans la construction - Briques de verre - Spécification et méthodesd'essai Reference number IS0 21690:2021(E) ISO @IS02021 IS0 21690:2021(E) COPYRIGHT PROTECTED DOCUMENT @ IS02021 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, withoutpriorwrittenpermission.Permission can berequestedfrom eitherIso at theaddress below orIso'smemberbodyinthecountryoftherequester. ISO copyright office CP 401 · Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +4122 749 0111 Email: [email protected] Website: www.iso.org Published in Switzerland ii @ IS0 2021 - All rights reserved